Crash boxes function as impact energy absorbing elements which are arranged between a bumper, in particular a bumper transverse beam, and a longitudinal beam of a motor vehicle body, in order to be able to largely prevent damage to the supporting structure of the body in the case of a front or rear impact in the lower speed range. Known crash boxes are generally constructed as thin-walled, approximately rectangular-cubic elements of steel, aluminum or plastic. They can be produced by joining from pressed sheet metal shells or in one piece, for example as an extrusion-molded or respectively extruded aluminum profile.
A mechanical impulse or a corresponding kinetic energy acting in the case of load on the bumper or respectively on the bumper transverse beam, on exceeding predetermined thresholds can lead to a targeted deformation of the crash box which is constructed as an energy absorption unit, and in so doing can largely protect the longitudinal beam of the vehicle body adjoining the crash box from damage.
The most varied of ways exist for fastening crash boxes on the longitudinal beam. So-called stick-in fastening concepts make provision, for example, to insert the crash box with a fastening profile facing the longitudinal beam into the profile cross-section of the associated longitudinal beam at least in parts, and in so doing to connect with one another, preferably detachably, overlapping profile regions of crash box and longitudinal beam which come directly to abutment, for instance to screw them to one another.
Thus, for example from DE 10 2005 051 764 B4 a crash box is known which is divided into two sections, which has a fastening section engaging into the longitudinal beam and a deformation section arranged before the front face of the longitudinal beam. The deformation section is composed here of an upper and a lower half shell, which in the case of a construction made of metal are connected with one another by welding. As a further component, that crash box has a flange plate with a restructuring formed thereon in one piece, which forms the fastening section engaging into the longitudinal beam. In terms of assembly technology, a pre-assembled crash box is introduced into the longitudinal beam, until the flange plate comes to abut against a front flange of the longitudinal beam, constructed in a corresponding manner hereto.
Such a crash box has a relatively complex construction and requires a separate reciprocal fastening or joining of fastening section and deformation section.
Alongside this, in the case of screwed stick-in fastenings, comparatively high point loads may occur in the region of the screws and screw holes. So that some stability can be provided, such screws and screw bolts and fastening holes corresponding herewith may be constructed so as to be sufficiently stable and thick-walled.
Accordingly, it may be desirable to provide a crash box which has an improved behavior transferring force and impact energy with regard to an introduction of force or energy into an adjoining longitudinal beam. It is also desirable to provide a crash box that is able to be produced at a lower cost, in a space-saving manner and is simple to install. Further, it is desirable to provide a crash box with a reduced weight. In addition, other objects, desirable features and characteristics will become apparent from the subsequent summary and detailed description, and the appended claims, taken in conjunction with the accompanying drawings and this background.